U.S. patent application number 10/005865 was filed with the patent office on 2003-05-08 for multi-port fuel injection nozzle and system and method incorporating same.
Invention is credited to Parrish, Scott E..
Application Number | 20030084883 10/005865 |
Document ID | / |
Family ID | 21718127 |
Filed Date | 2003-05-08 |
United States Patent
Application |
20030084883 |
Kind Code |
A1 |
Parrish, Scott E. |
May 8, 2003 |
Multi-port fuel injection nozzle and system and method
incorporating same
Abstract
A technique is provided for enhancing fluid flow in an outwardly
opening nozzle assembly. A flow enhancement assembly is provided
adjacent an exit from an outwardly opening poppet to provide
desired spray characteristics. The flow enhancement assembly
includes converging and diverging passages and a plurality of ports
to form a spray.
Inventors: |
Parrish, Scott E.;
(Farmington Hills, MI) |
Correspondence
Address: |
Tait R. Swanson
Fletcher, Yoder & Van Someren
P.O. Box 692289
Houston
TX
77269-2289
US
|
Family ID: |
21718127 |
Appl. No.: |
10/005865 |
Filed: |
November 8, 2001 |
Current U.S.
Class: |
123/500 ;
239/585.1 |
Current CPC
Class: |
F02B 61/045 20130101;
F02B 23/101 20130101; F02B 2075/1816 20130101; F02M 63/06 20130101;
F02M 57/027 20130101; F02M 61/08 20130101; F02B 2075/1824 20130101;
F02B 2075/025 20130101; F02M 61/1853 20130101; F02M 61/162
20130101; F02B 75/22 20130101 |
Class at
Publication: |
123/500 ;
239/585.1 |
International
Class: |
F02M 037/04 |
Claims
What is claimed is:
1. A nozzle comprising: an outwardly opening poppet disposed in a
conduit, comprising: a fluid passage section; and a head section
removably seated against a forward portion of the conduit; and a
spray formation assembly disposed adjacent the forward portion,
comprising: a flow enhancement passage comprising a contracting
passage and an expanding passage; and a plurality of ports coupled
to the flow enhancement passage.
2. The nozzle of claim 1, wherein the fluid passage section
comprises a ring-shaped passage formed between the outwardly
opening poppet and the conduit.
3. The nozzle of claim 1, wherein the fluid passage section
comprises rear and forward sections, which form rear and forward
cavities between the outwardly opening poppet and the conduit.
4. The nozzle of claim 2, wherein the fluid passage section
comprises a guide section disposed between the rear and forward
sections, the guide section having at least one passageway coupling
the rear and forward cavities.
5. The nozzle of claim 1, wherein the head section comprises an
expanding section.
6. The nozzle of claim 5, wherein the head section comprises a
contracting section.
7. The nozzle of claim 6, wherein the expanding and contracting
sections comprise conical geometries.
8. The nozzle of claim 1, wherein the spray formation assembly is
configured to provide a substantially uniform distribution of fluid
droplets from the plurality of ports.
9. The nozzle of claim 8, wherein the spray formation assembly is
configured to provide a conical spray pattern.
10. The nozzle of claim 9, wherein the flow enhancement passage
comprises a ring-shaped cross-section.
11. The nozzle of claim 10, wherein the contracting passage
comprises a conical geometry.
12. The nozzle of claim 10, wherein the expanding passage comprises
a washer-shaped geometry.
13. The nozzle of claim 10, wherein the outwardly opening poppet is
movable between seated and unseated orientations, the unseated
orientation forming a ring-shaped passage between the forward
portion and the head section.
14. The nozzle of claim 13, wherein a front face of the head
section abuts an inner face of the spray formation assembly in the
unseated orientation of the outwardly opening poppet.
15. The nozzle of claim 1, wherein the plurality of ports comprises
a passage geometry configured to provide a desired fluid
dispersion.
16. The nozzle of claim 15, wherein the passage geometry comprises
a cylindrical section.
17. The nozzle of claim 15, wherein the passage geometry comprises
a conical section.
18. The nozzle of claim 1, comprising a spring assembly coupled to
the outwardly opening poppet for biasing the head section inwardly
toward the forward portion.
19. The nozzle of claim 1, comprising a fuel supply coupled to the
fluid passage section.
20. A spray system, comprising: a nozzle assembly comprising: an
outwardly opening poppet movably disposed between seated and
unseated positions in a conduit; and a flow enhancement assembly
disposed forward the outwardly opening poppet, wherein the flow
enhancement assembly comprises converging and diverging ring-shaped
passages.
21. The spray system of claim 20, comprising a fluid supply
assembly coupled to the nozzle assembly.
22. The spray system of claim 21, wherein the fluid supply assembly
comprises a pump assembly.
23. The spray system of claim 22, wherein the fluid supply assembly
comprises a reciprocating drive assembly coupled to the pump
assembly.
24. The spray system of claim 22, comprising a timing assembly
coupled to the pump assembly, wherein the timing assembly is
configured to coordinate fuel injection by the nozzle assembly with
ignition by an ignition assembly.
25. The spray system of claim 20, wherein the nozzle assembly
comprises a spring assembly coupled to the outwardly opening poppet
for biasing the outwardly opening poppet inwardly toward the seated
position.
26. The spray system of claim 20, wherein the outwardly opening
poppet comprises rear and forward sections, which form rear and
forward cavities between the outwardly opening poppet and the
conduit.
27. The spray system of claim 26, wherein the outwardly opening
poppet comprises a guide section disposed between the rear and
forward sections, the guide section having at least one passageway
coupling the rear and forward cavities.
28. The spray system of claim 20, wherein the outwardly opening
poppet comprises a head section having a conical geometry.
29. The spray system of claim 28, wherein the conical geometry
comprises converging and diverging sections.
30. The spray system of claim 20, wherein a ring-shaped passage is
formed between the conduit and the outwardly opening poppet in the
unseated position.
31. The spray system of claim 30, wherein a front face of the
outwardly opening poppet abuts an inner face of the flow
enhancement assembly in the unseated position of the outwardly
opening poppet.
32. The spray system of claim 20, wherein the flow enhancement
assembly comprises a plurality of ports coupled to the converging
and diverging ring-shaped passages.
33. The spray system of claim 32, wherein the plurality of ports
comprises a passage geometry configured to provide a desired fluid
dispersion from each of the plurality of ports.
34. The spray system of claim 33, wherein the plurality of ports
are configured for collectively forming a conical spray pattern
having a substantially uniform distribution of droplets through a
cross-section of the conical spray pattern.
35. The spray system of claim 20, wherein at least one of the
converging and diverging ring-shaped passages comprises a conical
geometry.
36. The spray system of claim 35, wherein at least one of the
converging and diverging ring-shaped passages comprises a
washer-shaped geometry.
37. A combustion engine, comprising: a combustion chamber; an
ignition assembly coupled to the combustion chamber; a spray
assembly coupled to the combustion chamber, comprising: an
outwardly opening flow controller disposed in a conduit; and a
forward flow assembly disposed adjacent the outwardly opening flow
controller, wherein the forward flow assembly comprises converging
and diverging passages; and a fuel delivery assembly coupled to the
spray assembly.
38. The combustion engine of claim 37, wherein the outwardly
opening flow controller comprises a poppet movably disposed between
seated and unseated positions in the conduit.
39. The combustion engine of claim 37, wherein the outwardly
opening flow controller comprises rear and forward sections, which
form rear and forward cavities between the outwardly opening flow
controller and the conduit.
40. The combustion engine of claim 39, wherein the outwardly
opening flow controller comprises a guide section disposed between
the rear and forward sections, the guide section having at least
one passageway coupling the rear and forward cavities.
41. The combustion engine of claim 37, wherein a ring-shaped
passage is formed between the conduit and the outwardly opening
flow controller in the unseated position.
42. The combustion engine of claim 37, wherein the forward flow
assembly comprises a plurality of ports coupled to the converging
and diverging passages.
43. The combustion engine of claim 42, wherein the converging and
diverging passages have a ring-shaped cross-section.
44. The combustion engine of claim 37, wherein the fuel delivery
assembly comprises a pump assembly.
45. The combustion engine of claim 44, wherein the fuel delivery
assembly comprises a reciprocating drive assembly coupled to the
pump assembly.
46. The combustion engine of claim 44, comprising a timing assembly
coupled to the spray assembly and the ignition assembly, wherein
the timing assembly is configured to coordinate fuel injection by
the spray assembly with ignition by the ignition assembly.
47. A method for forming a spray from an outwardly opening nozzle
assembly, comprising: passing fluid through a flow enhancement
assembly forward an outwardly opening poppet disposed in a fluid
conduit, the flow enhancement assembly comprising converging and
diverging passages having a ring-shaped cross-section; and passing
the fluid through a plurality of ports coupled to the flow
enhancement assembly.
48. The method of claim 47, wherein passing the fluid through the
flow enhancement assembly comprises passing the fluid through a
conical-shaped passage geometry.
49. The method of claim 48, wherein passing the fluid through the
flow enhancement assembly comprises passing the fluid through a
washer-shaped passage geometry.
50. The method of claim 49, wherein passing the fluid through the
flow enhancement assembly comprises inletting the fluid to the
converging and diverging passages from a ring-shaped passage formed
between the outwardly opening poppet and the fluid conduit in an
unseated position.
51. The method of claim 50, wherein inletting the fluid comprises
passing the fluid through the fluid conduit about a depressed
portion of the outwardly opening poppet.
52. The method of claim 51, wherein passing the fluid through the
fluid conduit comprises passing the fluid through a guide section
formed between forward and rear depressed portions of the outwardly
opening poppet.
53. The method of claim 50, wherein inletting the fluid comprises
reciprocally driving a head portion of the outwardly opening poppet
out of a seated position and springably returning the head portion
back into the seated position.
54. The method of claim 47, wherein passing the fluid through the
flow enhancement assembly comprises mixing the fluid through a
conical-shaped converging passage and a washer-shaped diverging
section.
55. The method of claim 54, comprising pumping the fluid into the
fluid conduit.
56. The method of claim 55, comprising spraying the fluid from the
plurality of ports into a combustion chamber.
57. The method of claim 56, comprising temporally coordinating a
spray pulse of the fluid with an ignition pulse to ignite the fluid
within the combustion chamber.
58. A method of forming a spray assembly, comprising: providing an
outwardly opening nozzle assembly; and coupling a spray enhancement
assembly to an exit of the outwardly opening nozzle assembly, the
spray enhancement assembly comprising converging and diverging
passages and a plurality of spray formation ports.
59. The method of claim 58, wherein providing the outwardly opening
nozzle assembly comprises movably disposing a poppet in a fluid
conduit, and forming a ring-shaped passage between the fluid
conduit and the poppet in an unseated position relative to the
fluid conduit.
60. The method of claim 59, comprising coupling a spring assembly
to the poppet to bias the poppet inwardly toward a seated position
relative to the fluid conduit.
61. The method of claim 58, comprising coupling a pump assembly to
the fluid conduit.
62. The method of claim 58, wherein coupling the spray enhancement
assembly to the exit comprises forming the converging and diverging
passages symmetrically about a longitudinal axis of the outwardly
opening nozzle assembly.
63. The method of claim 62, wherein the converging and diverging
passages comprise a ring-shaped cross-section.
64. The method of claim 62, comprising orienting the plurality of
spray formation ports in a ring-shaped pattern.
65. The method of claim 62, comprising forming a passage geometry
in the plurality of ports to provide a desired dispersion of
fluid.
66. The method of claim 65, wherein forming the passage geometry
comprises forming a conical passage section having a desired
dispersion angle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of
internal combustion engine injection systems. More particularly,
the invention relates to a technique for controlling fluid flow and
spray characteristics of a spray assembly by providing a flow
enhancement assembly near the exit of an outwardly opening
poppet.
[0003] 2. Description of the Related Art
[0004] In fuel-injected engines, it is generally considered
desirable that each injector delivers approximately the same
quantity of fuel in approximately the same temporal relationship to
the engine for proper operation. It is also well known that the
fuel-air mixture affects the combustion process and the formation
of pollutants, such as Sulfur Oxides, Nitrogen Oxides,
Hydrocarbons, and particulate matter. Although combustion engines
utilize a variety of mixing techniques to improve the fuel-air
mixture, many combustion engines rely heavily on spray assemblies
to disperse fuel throughout a combustion chamber. These spray
assemblies may produce a variety of spray patterns, such as a
hollow or solid conical spray pattern, which affect the overall
fuel-air mixture in the combustion chamber. It is generally
desirable to provide a uniform fuel-air mixture to optimize the
combustion process and to eliminate pollutants. However,
conventional combustion engines continue to operate inefficiently
and produce pollutants due to poor fuel-air mixing in the
combustion chamber.
[0005] Accordingly, the present technique provides various unique
features to overcome the disadvantages of existing spray systems
and to improve the fuel-air mixture in combustion engines. In
particular, unique features are provided to enhance the fluid flow
through an outwardly opening nozzle assembly to provide desired
spray characteristics.
SUMMARY OF THE INVENTION
[0006] The present technique offers a design for internal
combustion engines which contemplates such needs. The technique is
applicable to a variety of fuel injection systems, and is
particularly well suited to pressure pulsed designs, in which fuel
is pressurized for injection into a combustion chamber by a
reciprocating electric motor and pump. However, other injection
system types may benefit from the technique described herein,
including those in which fuel and air are admitted into a
combustion chamber in mixture. Accordingly, a technique is provided
for enhancing fluid flow in an outwardly opening nozzle assembly. A
flow enhancement assembly is provided adjacent an exit from an
outwardly opening poppet to provide desired spray characteristics.
The flow enhancement assembly includes converging and diverging
passages and a plurality of ports to form a spray.
[0007] In one aspect, the present technique provides a nozzle
comprising an outwardly opening poppet disposed in a conduit and a
spray formation assembly disposed adjacent a forward portion of the
conduit. The outwardly opening poppet includes a fluid passage
section and a head section removably seated against the forward
portion. The spray formation assembly includes a flow enhancement
passage comprising a contracting passage and an expanding passage.
The spray formation assembly also has a plurality of ports coupled
to the flow enhancement passage.
[0008] In another aspect, the present technique provides a
combustion engine comprising a combustion chamber, an ignition
assembly coupled to the combustion chamber, a spray assembly
coupled to the combustion chamber, and a fuel delivery assembly
coupled to the spray assembly. The spray assembly includes an
outwardly opening flow controller disposed in a conduit and a
forward flow assembly disposed adjacent the outwardly opening flow
controller. In this embodiment, the forward flow assembly has
converging and diverging passages.
[0009] In another aspect, the present technique provides a method
for forming a spray from an outwardly opening nozzle assembly. The
method comprises passing fluid through a flow enhancement assembly
forward an outwardly opening poppet disposed in a fluid conduit.
The flow enhancement assembly includes converging and diverging
passages having a ring-shaped cross-section. The method also
comprises passing the fluid through a plurality of ports coupled to
the flow enhancement assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing and other advantages of the invention will
become apparent upon reading the following detailed description and
upon reference to the drawings in which:
[0011] FIG. 1 is a side view of a marine propulsion device
embodying an outboard drive or propulsion unit adapted for mounting
to a transom of a watercraft;
[0012] FIG. 2 is a cross-sectional view of the combustion
engine;
[0013] FIG. 3 is a diagrammatical representation of a series of
fluid pump assemblies applied to inject fuel into an internal
combustion engine;
[0014] FIG. 4 is a partial cross-sectional view of an exemplary
pump in accordance with aspects of the present technique for use in
displacing fluid under pressure, such as for fuel injection into a
chamber of an internal combustion engine as shown in FIG. 3;
[0015] FIG. 5 is a partial cross-sectional view of the pump
illustrated in FIG. 4 energized to an open position during a
pumping phase of operation;
[0016] FIG. 6 is a partial cross-sectional view of an exemplary
nozzle assembly in a closed position, as illustrated in FIG. 4;
[0017] FIG. 7 is a partial cross-sectional view of the nozzle
assembly in the open position, as illustrated in FIG. 5;
[0018] FIGS. 8A and B are front views of the nozzle assembly
illustrated in FIGS. 6-7 illustrating exemplary port configurations
for spray formation;
[0019] FIG. 9 is a cross-sectional view of an exemplary conical
spray formed by the nozzle assembly illustrated in FIGS. 6-8;
[0020] FIG. 10 is a cross-sectional view of the conical spray
having a substantially solid or uniform distribution of droplets;
and
[0021] FIG. 11 is a cross-sectional view of the conical spray
having a multi-group distribution of droplets.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0022] The present technique will be described with respect to a
2-cycle outboard marine engine as illustrated in FIGS. 1-2.
However, it will be appreciated that this invention is equally
applicable for use with a 4-cycle engine, a diesel engine, or any
other type of internal combustion engine having at least one fuel
injector, which may have one or more geometrically varying fluid
passageways leading to a nozzle exit. The present technique is also
applicable in other applications utilizing fluid spray assemblies,
such as a nozzle producing a hollow or solid cone-shaped droplet
spray.
[0023] FIG. 1 is a side view of a marine propulsion device
embodying an outboard drive or propulsion unit 10 adapted to be
mounted on a transom 12 of a watercraft for pivotal tilting
movement about a generally horizontal tilt axis 14 and for pivotal
steering movement about a generally upright steering axis 16. The
drive or propulsion unit 10 has a housing 18, wherein a
fuel-injected, two-stroke internal combustion engine 20 is disposed
in an upper section 22 and a transmission assembly 24 is disposed
in a lower section 26. The transmission assembly 24 has a drive
shaft 28 drivingly coupled to the combustion engine 20, and
extending longitudinally through the lower section 26 to a
propulsion region 30 whereat the drive shaft 28 is drivingly
coupled to a propeller shaft 32. Finally, the propeller shaft 32 is
drivingly coupled to a prop 34 for rotating the prop 34, thereby
creating a thrust force in a body of water. In the present
technique, the combustion engine 20 may embody a four-cylinder or
six-cylinder V-type engine for marine applications, or it may
embody a variety of other combustion engines with a suitable design
for a desired application, such as automotive, industrial, etc.
[0024] FIG. 2 is a cross-sectional view of the combustion engine
20. For illustration purposes, the combustion engine 20 is
illustrated as a two-stroke, direct-injected, internal combustion
engine having a single piston and cylinder. As illustrated, the
combustion engine 20 has an engine block 36 and a head 38 coupled
together and defining a firing chamber 40 in the head 38, a piston
cylinder 42 in the engine block 36 adjacent to the firing chamber
40, and a crankcase chamber 44 in the engine block 36 adjacent to
the piston cylinder 42. A piston 46 is slidably disposed in the
piston cylinder 42, and defines a combustion chamber 48 adjacent to
the firing chamber 40. A ring 50 is disposed about the piston 46
for providing a sealing force between the piston 46 and the piston
cylinder 42. A connecting rod 52 is pivotally coupled to the piston
46 on a side opposite from the combustion chamber 48, and the
connecting rod 52 is also pivotally coupled to an outer portion 54
of a crankshaft 56 for rotating the crankshaft 56 about an axis 58.
The crankshaft 56 is rotatably coupled to the crankcase chamber 44,
and preferably has counterweights 60 opposite from the outer
portion 54 with respect to the axis 58.
[0025] In general, an internal combustion engine such as engine 20
operates by compressing and igniting a fuel-air mixture. In some
combustion engines, fuel is injected into an air intake manifold,
and then the fuel-air mixture is injected into the firing chamber
for compression and ignition. As described below, the illustrated
embodiment intakes only the air, followed by direct fuel injection
and then ignition in the firing chamber.
[0026] A fuel injection system, having a fuel injector 62 disposed
in a first portion 64 of the head 38, is provided for directly
injecting a fuel spray 66 into the firing chamber 40. An ignition
assembly, having a spark plug 68 disposed in a second portion 70 of
the head 38, is provided for creating a spark 72 to ignite the
fuel-air mixture compressed within the firing chamber 40. The
control and timing of the fuel injector 62 and the spark plug 68
are critical to the performance of the combustion engine 20.
Accordingly, the fuel injection system and the ignition assembly
are coupled to a control assembly 74. As discussed in further
detail below, the uniformity of the fuel spray 66 is also critical
to performance of the combustion engine 20. The distribution of
fuel spray 66 affects the combustion process, the formation of
pollutants and various other factors.
[0027] In operation, the piston 46 linearly moves between a bottom
dead center position (not illustrated) and a top dead center
position (as illustrated in FIG. 2), thereby rotating the
crankshaft 56 in the process. At bottom dead center, an intake
passage 76 couples the combustion chamber 48 to the crankcase
chamber 44, allowing air to flow from the crankcase chamber 44
below the piston 46 to the combustion chamber 48 above the piston
46. The piston 46 then moves linearly upward from bottom dead
center to top dead center, thereby closing the intake passage 76
and compressing the air into the firing chamber 40. At some point,
determined by the control assembly 74, the fuel injection system is
engaged to trigger the fuel injector 62, and the ignition assembly
is engaged to trigger the spark plug 68. Accordingly, the fuel-air
mixture combusts and expands from the firing chamber 40 into the
combustion chamber 48, and the piston 46 is forced downwardly
toward bottom dead center. This downward motion is conveyed to the
crankshaft 56 by the connecting rod 52 to produce a rotational
motion of the crankshaft 56, which is then conveyed to the prop 34
by the transmission assembly 24 (as illustrated in FIG. 1). Near
bottom dead center, the combusted fuel-air mixture is exhausted
from the piston cylinder 42 through an exhaust passage 78. The
combustion process then repeats itself as the cylinder is charged
by air through the intake passage 76.
[0028] Referring now to FIG. 3, the fuel injection system 80 is
diagrammatically illustrated as having a series of pumps for
displacing fuel under pressure in the internal combustion engine
20. While the fluid pumps of the present technique may be employed
in a wide variety of settings, they are particularly well suited to
fuel injection systems in which relatively small quantities of fuel
are pressurized cyclically to inject the fuel into combustion
chambers of an engine as a function of the engine demands. The
pumps may be employed with individual combustion chambers as in the
illustrated embodiment, or may be associated in various ways to
pressurize quantities of fuel, as in a fuel rail, feed manifold,
and so forth. Even more generally, the present pumping technique
may be employed in settings other than fuel injection, such as for
displacing fluids under pressure in response to electrical control
signals used to energize coils of a drive assembly, as described
below. Moreover, the system 80 and engine 20 may be used in any
appropriate setting, and are particularly well suited to two-stroke
applications such as marine propulsion, outboard motors,
motorcycles, scooters, snowmobiles and other vehicles.
[0029] In the exemplary embodiment shown in FIG. 3, the fuel
injection system 80 has a fuel reservoir 81, such as a tank for
containing a reserve of liquid fuel. A first pump 82 draws the fuel
from the reservoir 81 through a first fuel line 83a, and delivers
the fuel through a second fuel line 83b to a separator 84. While
the system may function adequately without a separator 84, in the
illustrated embodiment, separator 84 serves to insure that the fuel
injection system downstream receives liquid fuel, as opposed to
mixed phase fuel. A second pump 85 draws the liquid fuel from
separator 84 through a third fuel line 83c and delivers the fuel,
through a fourth fuel line 83d and further through a cooler 86, to
a feed or inlet manifold 87 through a fifth fuel line 83e. Cooler
86 may be any suitable type of fluid cooler, including both air and
liquid heater exchangers, radiators, and the like.
[0030] Fuel from the feed manifold 87 is available for injection
into combustion chambers of engine 20, as described more fully
below. A return manifold 88 is provided for recirculating fluid not
injected into the combustion chambers of the engine. In the
illustrated embodiment a pressure regulating valve 89 is coupled to
the return manifold 88 through a sixth fuel line 83f and is used
for maintaining a desired pressure within the return manifold 88.
Fluid returned via the pressure regulating valve 89 is recirculated
into the separator 84 through a seventh fuel line 83g where the
fuel collects in liquid phase as illustrated at reference numeral
90. Gaseous phase components of the fuel, designated by referenced
numeral 91 in FIG. 3, may rise from the fuel surface and, depending
upon the level of liquid fuel within the separator, may be allowed
to escape via a float valve 92. The float valve 92 consists of a
float that operates a ventilation valve coupled to a ventilation
line 93. The ventilation line 93 is provided for permitting the
escape of gaseous components, such as for repressurization,
recirculation, and so forth. The float rides on the liquid fuel 90
in the separator 84 and regulates the ventilation valve based on
the level of the liquid fuel 90 and the presence of vapor in the
separator 84.
[0031] As illustrated in FIG. 3, engine 20 may include a series of
combustion chambers 48 for collectively driving the crankshaft 56
in rotation. As discussed with reference to FIG. 2, the combustion
chambers 48 comprise the space adjacent to a series of pistons 46
disposed in piston cylinders 42. As will be appreciated by those
skilled in the art, and depending upon the engine design, the
pistons 46 (FIG. 2) are driven in a reciprocating fashion within
each piston cylinder 42 in response to ignition, combustion and
expansion of the fuel-air mixture within each combustion chamber
48. The stroke of the piston within the chamber will permit fresh
air for subsequent combustion cycles to be admitted into the
chamber, while scavenging combustion products from the chamber.
While the present embodiment employs a straightforward two-stroke
engine design, the pumps in accordance with the present technique
may be adapted for a wide variety of applications and engine
designs, including other than two-stroke engines and cycles.
[0032] In the illustrated embodiment, the fuel injection system 80
has a reciprocating pump 94 associated with each combustion chamber
48, each pump 94 drawing pressurized fuel from the feed manifold
87, and further pressurizing the fuel for injection into the
respective combustion chamber 48. In this exemplary embodiment, the
fuel injector 62 (FIG. 2) may have a nozzle 95 (FIG. 3) for
atomizing the pressurized fuel downstream of each reciprocating
pump 94. While the present technique is not intended to be limited
to any particular injection system or injection scheme, in the
illustrated embodiment, a pressure pulse created in the liquid fuel
forces the fuel spray 66 to be formed at the mouth or outlet of the
nozzle 95, for direct, in-cylinder injection. The operation of
reciprocating pumps 94 is controlled by an injection controller 96
of the control assembly 74. The injection controller 96, which will
typically include a programmed microprocessor or other digital
processing circuitry and memory for storing a routine employed in
providing control signals to the pumps, applies energizing signals
to the pumps to cause their reciprocation in any one of a wide
variety of manners as described more fully below.
[0033] The control assembly 74 and/or the injection controller 96
may have a processor 97 or other digital processing circuitry, a
memory device 98 such as EEPROM for storing a routine employed in
providing command signals from the processor 97, and a driver
circuit 99 for processing commands or signals from the processor
97. The control assembly 74 and the injection controller 96 may
utilize the same processor 97 and memory as illustrated in FIG. 3,
or the injection controller 96 may have a separate processor and
memory device. The driver circuit 99 may be constructed with
multiple circuits or channels, each individual channel
corresponding with a reciprocating pump 94. In operation, a command
signal may be passed from the processor 97 to the driver circuit
99, which responds by generating separate drive signals for each
channel. These signals are carried to each individual pump 94 as
represented by individual electric connections EC1, EC2, EC3 and
EC4. Each of these connections corresponds with a channel of the
driver circuit 99. The operation and logic of the control assembly
74 and injection controller 96 will be discussed in greater detail
below.
[0034] Specifically, FIG. 4 illustrates the internal components of
a pump assembly including a drive section and a pumping section in
a first position wherein fuel is introduced into the pump for
pressurization. FIG. 5 illustrates the same pump following
energization of a solenoid coil to drive a reciprocating assembly
and thus cause pressurization of the fuel and its expulsion from
the pump. It should be borne in mind that the particular
configurations illustrated in FIGS. 4 and 5 are intended to be
exemplary only. Other variations on the pump may be envisaged,
particularly variants on the components used to pressurize the
fluid and to deliver the fluid to a downstream application.
[0035] In the presently contemplated embodiment, a pump and nozzle
assembly 100, as illustrated in FIGS. 4 and 5, is particularly well
suited for application in an internal combustion engine, as
illustrated in FIGS. 1-3. Moreover, in the embodiment illustrated
in FIGS. 4 and 5, a nozzle assembly is installed directly at an
outlet of a pump section, such that the pump 94 and the nozzle 95
of FIG. 3 are incorporated into a single assembly 100. As indicated
above, in appropriate applications, the pump 94 may be separated
from the nozzle 95, such as for application of fluid under pressure
to a manifold, fuel rail, or other downstream component. Thus, the
fuel injector 62 described with reference to FIG. 2 may comprise
the nozzle 95, the pump and nozzle assembly 100, or other designs
and configurations capable of fuel injection.
[0036] Referring to FIG. 4, an embodiment is shown wherein the
fluid actuators and fuel injectors are combined into a single unit,
or pump-nozzle assembly 100. The pump-nozzle assembly 100 is
composed of three primary subassemblies: a drive section 102, a
pump section 104, and a nozzle 106. The drive section 102 is
contained within a solenoid housing 108. A pump housing 110 serves
as the base for the pump-nozzle assembly 100. The pump housing 110
is attached to the solenoid housing 108 at one end and to the
nozzle 106 at an opposite end.
[0037] There are several flow paths for fuel within pump-nozzle
assembly 100. Initially, fuel enters the pump-nozzle assembly 100
through the fuel inlet 112. Fuel can flow from the fuel inlet 112
through two flow passages, a first passageway 114 and a second
passageway 116. A portion of fuel flows through the first
passageway 114 into an armature chamber 118. For pumping, fuel also
flows through the second passageway 116 to a pump chamber 120. Heat
and vapor bubbles are carried from the armature chamber 118 by fuel
flowing to an outlet 122 through a third fluid passageway 124. Fuel
then flows from the outlet 122 to the return manifold 88 (see FIG.
3).
[0038] The drive section 102 incorporates a linear electric motor.
In the illustrated embodiment, the linear electric motor is a
reluctance gap device. In the present context, reluctance is the
opposition of a magnetic circuit to the establishment or flow of a
magnetic flux. A magnetic field and circuit are produced in the
motor by electric current flowing through a coil 126. The coil 126
is electrically coupled by leads 128 to a receptacle 130, which is
coupled by conductors (not shown) to an injection controller 96 of
the control assembly 74. Magnetic flux flows in a magnetic circuit
132 around the exterior of the coil 126 when the coil is energized.
The magnetic circuit 132 is composed of a material with a low
reluctance, typically a magnetic material, such as ferromagnetic
alloy, or other magnetically conductive materials. A gap in the
magnetic circuit 132 is formed by a reluctance gap spacer 134
composed of a material with a relatively higher reluctance than the
magnetic circuit 132, such as synthetic plastic.
[0039] A reciprocating assembly 144 forms the linear moving
elements of the reluctance motor. The reciprocating assembly 144
includes a guide tube 146, an armature 148, a centering element 150
and a spring 152. The guide tube 146 is supported at the upper end
of travel by the upper bushing 136 and at the lower end of travel
by the lower bushing 142. An armature 148 is attached to the guide
tube 146. The armature 148 sits atop a biasing spring 152 that
opposes the downward motion of the armature 148 and guide tube 146,
and maintains the guide tube and armature in an upwardly biased or
retracted position. Centering element 150 keeps the spring 152 and
armature 148 in proper centered alignment. The guide tube 146 has a
central passageway 154, which permits the flow of a small volume of
fuel when the guide tube 146 moves a given distance through the
armature chamber 118 as described below. Accordingly, the flow of
fuel through the central passageway 154 facilitates cooling and
acceleration of the guide tube 146, which is moved in response to
energizing the coil during operation.
[0040] When the coil 126 is energized, the magnetic flux field
produced by the coil 126 seeks the path of least reluctance. The
armature 148 and the magnetic circuit 132 are composed of a
material of relatively low reluctance. The magnetic flux lines will
thus extend around coil 126 and through magnetic circuit 132 until
the magnetic gap spacer 134 is reached. The magnetic flux lines
will then extend to armature 148 and an electromagnetic force will
be produced to drive the armature 148 downward towards the
reluctance gap spacer 134. When the flow of electric current is
removed from the coil by the injection controller 96, the magnetic
flux will collapse and the force of spring 152 will drive the
armature 148 upwardly and away from alignment with the reluctance
gap spacer 134. Cycling the electrical control signals provided to
the coil 126 produces a reciprocating linear motion of the armature
148 and guide tube 146 by the upward force of the spring 152 and
the downward force produced by the magnetic flux field on the
armature 148.
[0041] During the return motion of the reciprocating assembly 144 a
fluid brake within the pump-nozzle assembly 100 acts to slow the
upward motion of the moving portions of the drive section 102. The
upper portion of the solenoid housing 108 is shaped to form a
recessed cavity 135. An upper bushing 136 separates the recessed
cavity 135 from the armature chamber 118 and provides support for
the moving elements of the drive section at the upper end of
travel. A seal 138 is located between the upper bushing 136 and the
solenoid housing 108 to ensure that the only flow of fuel from the
armature chamber 118 to and from the recessed cavity 135 is through
fluid passages 140 in the upper bushing 136. In operation, the
moving portions of the drive section 102 will displace fuel from
the armature chamber 118 into the recessed cavity 135 during the
period of upward motion. The flow of fuel is restricted through the
fluid passageways 140, thus, acting as a brake on upward motion. A
lower bushing 142 is included to provide support for the moving
elements of the drive section at the lower travel limit and to seal
the pump section from the drive section.
[0042] While the first fuel flow path 114 provides proper dampening
for the reciprocating assembly as well as providing heat transfer
benefits, the second fuel flow path 116 provides the fuel for
pumping and, ultimately, for combustion. The drive section 102
provides the motive force to drive the pump section 104, which
produces a surge of pressure that forces fuel through the nozzle
106. As described above, the drive section 102 operates cyclically
to produce a reciprocating linear motion in the guide tube 146.
During a charging phase of the cycle, fuel is drawn into the pump
section 104. Subsequently, during a discharging phase of the cycle,
the pump section 104 pressurizes the fuel and discharges the fuel
through the nozzle 106, such as directly into the combustion
chamber 48 (see FIG. 3).
[0043] During the charging phase fuel enters the pump section 104
from the inlet 112 through an inlet check valve assembly 156. The
inlet check valve assembly 156 contains a ball 158 biased by a
spring 160 toward a seat 162. During the charging phase the
pressure of the fuel in the fuel inlet 112 will overcome the spring
force and unseat the ball 158. Fuel will flow around the ball 158
and through the second passageway 116 into the pump chamber 120.
During the discharging phase the pressurized fuel in the pump
chamber 120 will assist the spring 160 in seating the ball 158,
preventing any reverse flow through the inlet check valve assembly
156.
[0044] A pressure surge is produced in the pump section 104 when
the guide tube 146 drives a pump sealing member 164 into the pump
chamber 120. The pump sealing member 164 is held in a biased
position by a spring 166 against a stop 168. The force of the
spring 166 opposes the motion of the pump sealing member 164 into
the pump chamber 120. When the coil 126 is energized to drive the
armature 148 towards alignment with the reluctance gap spacer 134,
the guide tube 146 is driven towards the pump sealing member 164.
There is, initially, a gap 169 between the guide tube 146 and the
pump sealing member 164. Until the guide tube 146 transits the gap
169 there is essentially no increase in the fuel pressure within
the pump chamber 120, and the guide tube and armature are free to
gain momentum by flow of fuel through passageway 154. The
acceleration of the guide tube 146 as it transits the gap 169
produces the rapid initial surge in fuel pressure once the guide
tube 146 contacts the pump sealing member 164, which seals
passageway 154 to pressurize the volume of fuel within the pump
chamber 120.
[0045] Referring generally to FIG. 5, a seal is formed between the
guide tube 146 and the pump sealing member 164 when the guide tube
146 contacts the pump sealing member 164. This seal closes the
opening to the central passageway 154 from the pump chamber 120.
The electromagnetic force driving the armature 148 and guide tube
146 overcomes the force of springs 152 and 166, and drives the pump
sealing member 164 into the pump chamber 120. This extension of the
guide tube into the pump chamber 120 causes an increase in fuel
pressure in the pump chamber 120 that, in turn, causes the inlet
check valve assembly 156 to seat, thus stopping the flow of fuel
into the pump chamber 120 and ending the charging phase. The volume
of the pump chamber 120 will decrease as the guide tube 146 is
driven into the pump chamber 120, further increasing pressure
within the pump chamber 120 and forcing displacement of the fuel
from the pump chamber 120 to the nozzle 106 through an outlet check
valve assembly 170. The fuel displacement will continue as the
guide tube 146 is progressively driven into the pump chamber
120.
[0046] Pressurized fuel flows from the pump chamber 120 through a
passageway 172 to the outlet check valve assembly 170. The outlet
check valve assembly 170 includes a valve disc 174, a spring 176
and a seat 178. The spring 176 provides a force to seat the valve
disc 174 against the seat 178. Fuel flows through the outlet check
valve assembly 170 when the force on the pump chamber side of the
valve disc 174 produced by the rise in pressure within the pump
chamber 120 is greater than the force placed on the outlet side of
the valve disc 174 by the spring 176 and any residual pressure
within the nozzle 106.
[0047] Once the pressure in the pump chamber 120 has risen
sufficiently to open the outlet check valve assembly 170, fuel will
flow from the pump chamber 120 to the nozzle 106. The nozzle 106 is
comprised of a nozzle housing 180, a passage 182, a poppet 184, a
retainer 186, and a spring 188. The poppet 184 is disposed within
the passage 182. The retainer 186 is attached to the poppet 184,
and spring 188 applies an upward force on the retainer 186 that
acts to hold the poppet 184 seated against the nozzle housing 180.
A volume of fuel is retained within the nozzle 106 when the poppet
184 is seated. The pressurized fuel flowing into the nozzle 106
from the outlet check valve assembly 170 pressurizes this retained
volume of fuel. The increase in fuel pressure applies a force that
unseats the poppet 184. Fuel flows through the opening created
between the nozzle housing 180 and the poppet 184 when the poppet
184 is unseated. The fuel is then mixed by a variable flow path
defined by a variety of flow enhancement geometries of the poppet
184 and a forward section, such as the inverted cone shape of the
poppet 184 and the expanding and contracting flow sections, as
illustrated in FIGS. 6, 7 and 9. The fuel then passes through a
plurality of ports, which project the fuel as a plurality of fluid
jets to form the desired spray pattern (e.g., fuel spray 66, 196).
The pump-nozzle assembly 100 may be coupled to a cylinder head 190,
such as the head 38 illustrated in FIG. 2, via male/female threads,
a flange assembly, or any other suitable mechanical coupling. Thus,
the fuel spray from the nozzle 106 may be injected directly into a
cylinder.
[0048] When the drive signal or current applied to the coil 126 is
removed, the drive section 102 will no longer drive the armature
148 towards alignment with the reluctance gap spacer 134, ending
the discharging phase and beginning a subsequent charging phase.
The spring 152 will reverse the direction of motion of the armature
148 and guide tube 146 away from the reluctance gap spacer 134.
Retraction of the guide tube from the pump chamber 120 causes a
drop in the pressure within the pump chamber, allowing the outlet
check valve assembly 170 to seat. The poppet 184 similarly retracts
and seats, and the spray of fuel into the cylinder is interrupted.
Following additional retraction of the guide tube, the inlet check
valve assembly 156 will unseat and fuel will flow into the pump
chamber 120 from the inlet 112. Thus, the operating cycle the
pump-nozzle assembly 100 returns to the condition shown in FIG.
4.
[0049] A detailed illustration of the nozzle 106 is provided in
FIGS. 6-10. In FIGS. 6, 7 and 9, cross-sectional side views of the
nozzle 106 are provided to illustrate exemplary geometries and
fluid flows through the nozzle 106. Front views of the nozzle 106
are provided in FIGS. 8A and 8B to illustrate various multi-port
configurations of the nozzle 106. As illustrated in FIG. 9, these
multiple ports are configured to project multiple fluid jets from
the nozzle 106 in a generally conic spray pattern, which may
eventually form a substantially uniform solid spray downstream of
the nozzle 106. For example, the cross-section of the conic spray
pattern may have a generally uniform droplet distribution or a
plurality of distinct groups of droplets corresponding to the
multiple ports/jets, as illustrated in detail by FIGS. 10 and 11.
In FIG. 6, the nozzle 106 is illustrated in a closed configuration
192. In FIGS. 7 and 9, the nozzle 106 is illustrated in an open
configuration 194 to facilitate fluid flow through the nozzle 106
and out through the multiple ports to form the generally conic
spray, which may have multiple distinct spray patterns or an
intermixed spray pattern (e.g., a substantially uniform solid
spray). As discussed in detail below, the geometry and
configuration of the nozzle 106 enhances the fluid flow and spray
characteristics of the nozzle 106.
[0050] As illustrated in FIG. 6, the nozzle 106 has the poppet 184
movably disposed in the passage 182 of the nozzle housing 180. The
nozzle housing 180 comprises a core section 200, a forward inner
section 202 disposed adjacent the core section 200, and a forward
outer section 204 disposed about the forward inner section 202 and
a forward portion 206 of the core section 200. Within the nozzle
106, a plurality of fluid flow passages are formed between the
foregoing sections to enhance the fluid flow and spray
characteristics. These fluid flow passages maybe symmetrically
arranged about a longitudinal centerline, or they may have a
symmetrical cross-section, such as a ring-shaped cross-section. As
illustrated, the passage 182 extends along a centerline 208 of the
core section 200. The passage 182 has a uniform cross section, such
as a cylindrical cross section, which extends along the centerline
208 to an expanding section 210 (e.g., a conical section) of the
core section 200 adjacent the forward inner section 202. The poppet
184 has a seat portion 212, which is seated against a seat portion
214 in the expanding section 210 adjacent the forward inner section
202. The poppet 184 also has a contracting section 216, which
extends into a front cavity 218 formed by a contracting section 220
and expanding section 222 (e.g., a ring-shaped or washer-shaped
section) of the forward inner section 202. The expanding section
222 extends into a set of ports 224, which may be symmetrically
disposed about a front section 226 of the forward outer section
204. As illustrated, the set of ports 224 have a cylindrical
passage 228 followed by an expanding passage 230 to facilitate a
desired fluid dispersion from the nozzle 106. It should also be
noted that the set of ports 224 may comprise any one or a
combination of contracting, expanding and cylindrical passages to
facilitate the desired fluid dispersion from the nozzle 106. For
example, if the set of ports 224 comprise a diverging/expanding
passage, then the fluid jets projecting from the set of ports 224
have a spray projection angle or spread that generally increases
with the angle and length of the diverging/expanding passage.
[0051] In the closed configuration 192 illustrated in FIG. 6, the
poppet 184 is seated against the core section 200 at the seat
portions 212 and 214 to prevent fluid flow into the front cavity
218 and out through the set of ports 224. However, when the
pressure has risen sufficiently in the pump chamber 120 to open the
outlet check valve assembly 170, fluid flows through the passage
182 about the poppet 184 to unseat the seat portion 212 of the
poppet 184 from the seat portion 214 of the core section 200.
Accordingly, fluid flows through the front cavity 218 and disperses
through the set of ports 224, as illustrated in the open
configuration 194 of FIGS. 7 and 9.
[0052] As illustrated in FIG. 6, the geometry of the poppet 184 and
the passage 182 forms a rear cavity 232 and a forward cavity 234,
which are disposed about a guide area 236. A set of passages 238 is
disposed about the guide area 236 between the surface of the poppet
184 and the passage 182. The rear cavity 232 is disposed near a
rear 240 of the poppet 184 and the passage 182, while the forward
cavity 234 is disposed adjacent the seat portions 212 and 214. In
this exemplary embodiment of the nozzle 106, the rear cavity 232
has a length 242, the guide area 236 has a length 244, and the
forward cavity 234 has a length 246. These lengths 242, 244, and
246 may have any suitable dimensions, such as in a conventional
nozzle assembly. However, the lengths 242, 244 and 246 may be
adapted to increase or decrease the turbulence (i.e., decrease or
increase the flow uniformity) of the fluid flowing through the
passage 182 adjacent the front cavity 218 and the set of ports
224.
[0053] The rear cavity 232 has a contracting section 248 near the
rear 240, followed by a central section 250 and an expanding
section 252. As illustrated, the central section 250 comprises a
cylindrical geometry, while the contracting and expanding sections
248 and 252 have conic geometries. The guide area 236, which is
disposed adjacent the expanding section 252, has the set of
passages 238 symmetrically disposed about the poppet 184. These
passages 238 may comprise a curved or linear geometry in any number
and configuration to allow fluid to pass through the guide area
236. In the forward cavity 234, the poppet 184 has a contracting
section 254 adjacent the guide area 236, followed by a central
section 256 and an expanding section 258. As illustrated, the
central section 256 comprises a cylindrical geometry, while the
contracting and expanding sections 254 and 258 have conic
geometries. The particular geometries of these sections 248, 250,
252, 254, 256 and 258 also can be adapted to induce a desired fluid
flow through the passage 182.
[0054] The geometry of the forward inner section 202 and the front
portion 226 of the forward outer section 204 are configured to
facilitate desired fluid flow characteristics, such as turbulence,
mixing and high velocities, prior to dispersion through the set of
ports 224. Accordingly, the enhanced fluid flow caused by the
contracting section 220, the expanding section 222 and the ports
224 may provide a distinct multi-jet spray, a relatively uniform
solid spray, or a semi-mixed spray composed of the multiple jets
projecting from the multiple ports. The particular geometrical
pattern, density and features of this spray also may vary with
axial distance from the nozzle 106. The foregoing configuration of
the forward inner section and ports 224 also may affect the size
and distribution of droplet sizes throughout the spray.
Accordingly, the forward inner section 202 and ports 224 may have
any suitable geometry to facilitate mixing and desirable flow
qualities. For example, the forward inner section 202 may have a
relatively jagged or zigzagging flow path to increase turbulence.
The jaggedness (i.e., degree of angles) of the zigzagging flow path
also controls the degree of turbulence in the fluid flow. Sharper
angles tend to increase the turbulence. As illustrated, the
contracting and expanding sections 220 and 222 of the forward inner
section 202 have conic and disk-shaped geometries, respectively,
which induce turbulence and mixing in the fluid flow. The ports 224
also may have any suitable geometry and position relative to the
contracting and expanding sections 220 and 222 to retain the
turbulent effects of the forward inner section 202 and to enhance
the dispersion of fluid as it exits the nozzle 106. For example,
the ports 224 may be positioned relatively closer to the abrupt
angle between the contracting and expanding sections 220 and 222 to
retain the turbulence in the fluid flowing through the ports
224.
[0055] In FIG. 7, exemplary fluid flows are illustrated for the
nozzle 106 in the open configuration 194, which is triggered by a
sufficient pressure increase in the pump chamber 120 to open the
outlet check valve assembly 170. Fluid is then fed into the passage
182 through an inlet 260, which extends through the core section
200 and into the rear cavity 232. As illustrated in FIGS. 7 and 9,
the fluid passes through the nozzle 106 as indicated by arrows 262,
264, 266, 268, 270, 272, and 274, which correspond to flow through
the inlet 260, the rear cavity 232, the set of passages 238
disposed about the guide area 236, the forward cavity 234, the
contracting section 220 of the front cavity 218, the expanding
section 222 of the front cavity 218, and through the set of ports
224. As illustrated in this open configuration 194, a front face
276 of the poppet 184 is disposed adjacent an inner surface 278 of
the forward outer section 204. As the poppet 184 is opened
outwardly toward the forward outer section 204, the nozzle 106
forms contracting, and expanding (e.g., zigzagging) passages, which
have a ring-shaped cross-section. Accordingly, the fluid flows
inwardly at an angle according to the arrows 270 and then outwardly
in the expanding section 222 according to the arrows 272. The fluid
then flows forward through the ports 224 and disperses according to
the arrows 274. As discussed above, this zigzagging flow pattern
through the front cavity 218 facilitates mixing and turbulence in
the fluid flow. The geometry of the ports 224 also affects the
turbulence levels and the characteristics of spray 196, as
illustrated in FIG. 9. For example, the ports 224 may embody
cylindrical passages, diverging or converging conical passages, or
any suitable combination of uniform or varying cross-sections. The
ports 224 also may embody angular passageways, which enhance or
direct the fluid flowing through the nozzle 106. Accordingly, the
angular or zigzagging passageways through the forward inner section
202 and the geometry of the ports 224 facilitate desired fluid flow
and spray characteristics (e.g., atomization, droplet dispersion,
mixing and uniformity, etc.).
[0056] The front 226 of the forward outer section 204 is
illustrated in further detail in FIGS. 8A and 8B, which are cross
sections of the front 226 illustrating exemplary patterns of the
ports 224. As discussed above, the front 226 may have any suitable
number of the ports 224, such as six or eight ports, as illustrated
in FIGS. 8A and 8B, respectively. It also should be noted that the
set of ports 224 are arranged symmetrically about the centerline
208 in the front 226. However, any other suitable geometry of the
forward inner section 202 and arrangement of the ports 224 is
within the scope of the present technique. The ports 224 may
include axially uniform and varying geometries, which may be formed
by drilling, punching, molding or any suitable manufacturing
process.
[0057] As illustrated by the dashed lines, the ports 224 are
symmetrically arranged within the expanding section 222 of the
front cavity 218. Depending on the desired flow volume and
characteristics, the ports 224 may have any suitable passage
geometry of uniform or varying cross-section, such as one or a
combination of a cylindrical passage, an expanding passage, and a
contracting passage. For example, as discussed above, the angle and
length of the foregoing uniform and varying cross-sections may be
varied to control the crosswise and lengthwise penetration of jets
projecting from the ports 224. A cylindrical geometry may provide a
narrow jet, which has a relatively narrow crosswise penetration and
a relatively long lengthwise penetration. An expanding geometry may
provide a broader jet, which has a relatively broader crosswise
penetration and a relatively shorter lengthwise penetration. If the
port has a combination of uniform and varying cross-sections, then
the effects of each section would increase with their relative
lengths. As illustrated in FIGS. 8A and 8B, the ports 224 have
cylindrical passages 228 and expanding passages 230. If the lengths
of the expanding passages 230 are increased relative to the
cylindrical passages 228, then the ports 224 may provide fluid jets
having relatively broader crosswise penetration and shallower
lengthwise penetration. The ports 224 also may be disposed at
angles to direct the fluid flow or facilitate intermixing of the
jets projecting from the ports 224. For example, the ports 224 may
be directed toward a desired target in a combustion chamber offset
from the nozzle 106. The ports also may have various curved or
linear cross sections to facilitate other desired flow properties
and spray characteristics.
[0058] As illustrated in FIG. 9, the nozzle 106 forms the spray 196
from the set of ports 224. The spray 196 has a relatively uniform
droplet distribution attributed to the geometries and flow patterns
within the nozzle 106. At a downstream distance 280 from the nozzle
106, the spray 196 has a width 282 that may be controlled by the
geometries of the forward inner section 202 and the ports 224. For
example, based on the distance 280 and the foregoing geometries,
the spray 196 may have a substantially uniform cross section 198 or
a multi-group cross-section 284 having a plurality of distinct
droplet groups 286, as illustrated in FIGS. 10 and 11,
respectively. The width 282 and corresponding cross sections 198
and 284 may be further enhanced by varying the zigzagging
geometries in the forward inner section 202 and the uniform and
varying passages through the front 226, as discussed above. For
example, if the ports 224 have cylindrical passages (e.g.,
cylindrical passages 228) extending through the front 226, then the
width 282 may be relatively narrower than a solid spray formed by
expanding passages (e.g., expanding passages 230). Accordingly, the
present technique may utilize a variety of geometries for the
poppet 184, the forward inner section 202, and the front 226 of the
forward outer section 204 (e.g., ports 224) to facilitate desired
flow and spray characteristics in this outwardly (or forward)
opening poppet configuration.
[0059] While the invention may be susceptible to various
modifications and alternative forms, specific embodiments have been
shown by way of example in the drawings and have been described in
detail herein. However, it should be understood that the invention
is not intended to be limited to the particular forms disclosed.
Rather, the invention is to cover all modifications, equivalents,
and alternatives falling within the spirit and scope of the
invention as defined by the following appended claims.
* * * * *